Activity of Bevacizumab in Patients With Low-Grade Serous Ovarian Carcinoma

Objectives: The aim of this study was to evaluate the antitumor activity of bevacizumab in low-grade serous ovarian carcinoma (LGSOC). Methods: We retrospectively identified patients with LGSOC treated with bevacizumab. Results: Twelve patients with LGSOC who received bevacizumab were identified. Eleven patients received bevacizumab alone. Only 1 (8.3%) of 12 patients had evidence of a partial response. Ten (90.9%) of the 11 patients were progression free at 6 months. All but 1 patient who received only 2 courses before treatment interruption had a progression-free survival (PFS) of greater than 6 months. The median PFS was 48 months (range, 5-123+ months). Three of the patients reported in this series had extended disease stabilization that lasted for 123+, 48, and 15+ months after progression-free intervals on prior chemotherapy regimens of 2.5, 4, and 7 months, respectively. The median overall survival was not reached at a median follow-up of 32 months, with only 1 of the 12 patients dying of disease. Conclusions: In our series, in patients with LGSOC treated primarily with bevacizumab, primarily as a single agent, a low response rate but very long PFS is observed. In addition, patients have had secondary PFS durations that exceeded their prior PFS, which is a sign of anticancer activity.